We have developed a nanofabrication and measurement system for nano-devices such as single electron transistors. This system can perform all of the required processes in ultrahigh vacuum, such as preparation of substrate surface, fabrication of metallic electrodes on a substrate using a precise mask deposition equipment, nanofabrication of gold dots and lines using a scanning tunneling microscope (STM), and measurement of electric properties of the nano-devices using a low temperature four-contact probe apparatus. Using a novel atom transfer method from the gold tips, highly reproducible fabrication of gold nano-dots and nano-lines have been demonstrated here. Some technical innovations required for this development are briefly introduced.